Alkenes are exceptionally attractive functional groups for synthesis. Newly discovered and significantly improved alkene functionalization reactions can have a direct impact on the efficiency of targeted synthesis. Therefore, the development of selective, practical alkene functionalization reactions is a continuing challenge facing chemists in both academia and industry. In this proposal, we target a new collection of alkene functionalization reactions that exploit Pd(II)-catalysis and its ability to promote both alkene nucleophilic addition reactions and cross-coupling processes to form multiple new C-C, C-H, or C-X bonds across the alkene framework. This reaction method development is coupled to careful mechanistic studies, which are designed to elucidate the fundamental features governing reaction outcomes, as well as to stimulate new reaction development and catalyst design. The current proposal is directed toward the development of new Pd-catalyzed olefin functionalization reactions using both oxidative and classical methods to generate Pd-alkyl intermediates. The reaction development described herein is focused on two significant goals: A) enabling new mechanistically-derived tactics for molecule synthesis by using innovative approaches to functionalize Pd-alkyl intermediates originally derived from an alkene (Aims 1 & 2), and B) exploiting our recently developed Heck reactions of electronically non-biased olefins to access important chiral building blocks, while also probing the factors that govern selective Pd-hydride insertion and -hydride elimination (Aim 3).